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 A034833 a(n) = n-th sept-factorial number divided by 6. 9
 1, 13, 260, 7020, 238680, 9785880, 469722240, 25834723200, 1601752838400, 110520945849600, 8399591884569600, 697166126419276800, 62744951377734912000, 6086260283640286464000, 632971069498589792256000, 70259788714343466940416000, 8290655068292529098969088000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..339 FORMULA a(n) = A049209(n)/6; a(n) = (7*n-1)(!^7)/6; a(n) = (1/6)*Product_{j=1..n} (7*j-1); a(n) = (1/6)*(7*n)! / (7^n * n! * A045754(n) * 2*A034829(n) * 3*A034830(n) * 4*A034831(n) * 5*A034832(n)). E.g.f.: (-1 + (1-7*x)^(-6/7))/6. MATHEMATICA FoldList[Times, 1, Rest[7*Range[20]-1]] (* Harvey P. Dale, Dec 15 2014 *) PROG (PARI) x='x+('x^30); Vec(serlaplace((-1 + (1-7*x)^(-6/7))/6)) \\ G. C. Greubel, Feb 22 2018 (MAGMA) [(&*[(7*k-1): k in [1..n]])/6: n in [1..30]]; // G. C. Greubel, Feb 24 2018 CROSSREFS Cf. A049209, A045754, A034829, A034830, A034831, A034832, A034834. Sequence in context: A321849 A034242 A142811 * A101004 A340936 A142931 Adjacent sequences:  A034830 A034831 A034832 * A034834 A034835 A034836 KEYWORD easy,nonn AUTHOR STATUS approved

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Last modified September 23 20:42 EDT 2021. Contains 347617 sequences. (Running on oeis4.)